Restoration of the patency of a stenosed terminal portion of the common bile duct by way of direct incision thereof through the anterior duodenal wall is known to have found still wider application as such an operation resumes natural bile discharge, establishes decomposition of both the bile system and the pancreatic ducts, and provides for better postoperative results.
Up till now this operation has been performed manually both in this country and abroad. However, manually carrying out this operation involves troubles in fixing and apposing the lips of the incised bile duct and duodenum, which may be accompanied by bleeding from the wound lips. Furthermore the line of sutures frequently proves to be uneven, inflammation is sustained for a prolonged period of time within the suture application zone, and biliary calculi tend to settle upon the suturing threads.
A great many surgical instruments for applying linear staple sutures and intersecting the tissue therebetween are known (cf., e.g., USSR Inventor's Certificate No. 125,867 Int. Cl. A61B 17/11 published in 1960), which are adapted to carry out surgical operations on the gastrointestinal tract.
Such surgical instruments mechanize the labour-consuming and lengthy process of manual application of surgical sutures. Of paramount importance is the fact that apart from considerably reducing the suture application time these instruments provide for a required degree of asepsis, tightness and hemostasis of the sutures applied, and correct arrangement of separate stitches, as well as reduce the amount of traumatism of the walls of the organs being sutured and of the adjacent tissues which favourably affects the course of the postoperative period. Moreover, the quality of operations is to a lesser extent dependent upon the surgeon's skill as compared to manual suturing.
However, the heretofore known surgical instruments for applying linear staple sutures and intersecting the tissue therebetween are generally not used in operations for restoring the patency of a stenosed terminal portion of the common bile duct, this being due to their constructional features, viz., the fact that the supporting jaw is arranged on the same axis with the mechanical actuator, whereby the entire instrument has to be introduced into the operative wound along with the surgeon's hand.
Another heretofore known surgical instrument for applying linear staple sutures and intersecting the tissue therebetween, adapted for stitching up blood vessels with two double-stitch sutures and simultaneously intersecting these vessels (cf. USSR Inventor's Certificate No. 371,926 Int. Cl. A61B 17/11, published in 1973) is adopted herein as the prototype.
The known instrument in question comprises an oblong u-shaped supporting body with a supporting jaw, which has depressions for bending of the staple and a die, a staple body having a carriage and a tail-piece and adapted to travel inside the u-shaped supporting body from its own drive, a staple magazine situated in the carriage of the supporting body and provided with a closed slot for the knife blade to pass and a number of slots for accommodating u-shaped staples expelled from these slots by means of an ejector.
This instrument is applicable whenever it becomes necessary to sever a vessel and apply a hermetically tight suture to both of its stumps, which is the case in, for example, treatment of pulmonary vessels in adult patients and major pulmonary vessels in children, as well as in abdominal surgery and surgery of the limbs.
However, the instrument features a heavy-section supporting jaw, which impedes insertion of the working member of the instrument into small diameter tubular organs or passing the same through narrow passages, specifically into the exit portion of the common bile duct, this being due to the fact that the supporting jaw carries an intermediate T-shaped bar, a die held thereto and a plastic backing pad. Besides, the supporting jaw tends to be weakened due to the presence of a slot adapted to accommodate part of the T-shaped bar and a number of holes.
The ejector of the known instrument is a rod with a head, whereon staple expelling prongs are secured and a detachable knife is situated therebetween.
Such a constructional arrangement of the staple ejector renders the known instrument inconvenient in handling since the knife must be sufficiently sharp for every operation, whereas final dressing of the knife is a complicated task requiring specialists to be carried out.
Provision of a plastic backing pad in the die slot brings about one more inconvenience in operation of the known instrument as the backing pad must be replaced for a succeeding operation.